A large number of cloth pieces such as towels are used in hotels, hospitals, and the like. Generally, those used cloth pieces are washed and dried at laundry plants for being reused in hotels, hospitals, and the like.
Cloth pieces are washed and dried at laundry plants, followed by an inspection for an imperfection such as dirt or a tear. Only cloth pieces without an imperfection are then folded by a folding machine.
In the case of a visual inspection of cloth pieces by a worker, determination of the quality may vary depending on a worker. Therefore, recently, an apparatus for inspecting a cloth piece performs this operation.
As an example of an apparatus for inspecting a cloth piece, Patent Literature 1 discloses an apparatus.
As shown in FIG. 7, the apparatus includes a series of conveying conveyers 101, and a camera 104 for inspecting a front face of a cloth piece conveyed through a conveying part 101A for a front-facing cloth piece and a camera 105 for inspecting a back face of the cloth piece conveyed through a conveying part 101B for a back-facing cloth piece in the series of the conveying conveyers 101.
A cloth piece is conveyed to the conveying part 101A for a front-facing cloth piece and the conveying part 101B for a back-facing cloth piece, and the cameras 104 and 105 pick up images thereof. This enables an inspection of the both front and back faces.
According to a result of the inspection, a cloth piece having dirt is subjected to rewashing, while a cloth piece having a tear is discarded. However, the cloth piece having a tear may be subjected to rewashing because a conventional apparatus for inspecting a cloth piece has difficulty in distinguishing between dirt and a tear. The cloth piece having a tear is to be washed for many times in the case. Improvement in processing efficiency has been therefore desired by reliably distinguishing between dirt and a tear and discarding a cloth piece having a tear.
In the case where pile fabric of a towel does not have dirt but a ground thereof has dirt, it is difficult to detect the dirt. Improvement of accuracy in detecting such dirt therefore has been desired, as well.